Sound reproduction system



Dec. 8, 1964 Filed April 18, 1962 E. L. SECHRIST SOUND REPRODUCTIONSYSTEM 3 Sheets-Sheet 1 INVENTOR.

EDWARD L. SECHRIST SMM M ATTORNEYS Dec. 8, 1964 E. L. SECHRIST SOUNDREPRODUCTION SYSTEM 7 3 Sheets-Sheet 2 Filed April 18, 1962 FIG. 5

FIG.

INVENTOR.

EDWARD L. SECHRIST BY ATTORNEYS Dec. 8, 1964 E. L. SECHRIST SOUNDREPRODUCTION SYSTEM Filed April 18, 1962 7 P as 24 5 3 Sheets-Sheet 5Ill/IA INVENTOR.

EDWARD L. SECHRIST ATTORNEYS United States Patent 3,16tl,2-25 SUUNE)REPRQDUCTIGN Sh l Edward L. dechrist, Syracuse, llnd. Filed Apr. 18,1962, Ser. No. lllhfid-tl 6 *Claims. ll. llfil -El) The presentinvention relates to a sound reproduction system and more particularlyto sound reproduction systerns of thin silhouette construction for useprimarily in stereo and hi-fi systems.

With the increase in popularity in recent years of stereophonic-highfidelity sound equipment and with the lowering of costs tor qualityequipment, the market has been greatly expanded for homes, ofiices andcommercial establishments. However, the conventional speaker enclosuresare relatively deep and large, and are not sufficiently versatile topermit them to be advantageously placed for most effective stereo soundreproduction, or in some instances to be installed and usedsatisfactorily. This is particularly true in small homes, apartments andbusiness places of limited or crowded area. Efforts have been made inthe past to develop and perfect thin silhouette speakers for stereo andhigh fidelity systems; however, difiiculty has been encountered inobtaining the natural bass and low tones without the use ot enclosuresor" substantial depth. it is therefore one of the principal objects ofthe present invention to provide a high fidelity sound reproductionsytem which utilizes a thin silhouette enclosure without sacrificingoptimum tone quality and range, and which is more compact and versatilefor all uses than the conventional enclosures, either stand, table orconsole, or permanently installed cabinet or wall types.

Another object of the invention is to provide a sound reproductionsystem and enclosure which is sufiiciently thin, small in size and lightin weight that it can be hung on a wall in the same manner as aconventional picture and which provides a relatively large panel withina frame for receiving a picture, mural or attractive grid which rendersthe overall appearance similar to that of a conventional picture ordecorative piece.

Still another object of the invention is to provide a wall-typestereophonic speaker having a thin silhouette and yet being capable ofproducing the high quality tone reproduction over the complete highfidelity range as the standard console speakers.

A further object is to provide a thin stereo speaker onclosure which canbe easily moved and installed at any advantageous place and which issimple in construction and design, utilizing a series of longitudinal orvertical superposed forward to back channels or chambers to reproducecharacteristic high quality low and bass tones.

Another object of the invention is to provide a stereo phonic and orhigh fidelity sound reproduction unit having a compound sound chamberfor reproducing the seven basic music tones, with a chamber for eachtone to produce the proper resonance and vibration.

Additional objects and advantages of the present invention will becomeapparent from the following description and accompanying drawings,wherein:

FIGURE 1 is a front elevational View of a stereophonie high fidelitysound reproducing enclosure embodying the present invention;

FIGURE 2 is a side elevational View of the sound reproduction enclosureshown in FlGURE 1;

FIGURE 3 is an enlarged front elevational view of the sound reproductionenclosure shown in FEGURES 1 and 2, with the picture shown thereonremoved in order to show certain details and relationships in theconstruction of the present system;

FIGURE 4 is a rear elevational view of the inside of the soundreproduction enclosure with the back of the hce enclosure removed, inorder to illustrate the relationship of the various parts forming thestructure;

5 is a vertical cross sectional view of the enclosure embodying thepresent system, the section being taken on line 5-5 of FIGURE 4;

FIGURE 6 is a rear elevational view of a modified form of the presentsound reproduction system;

FEGURE 7 is a vertical cross sectional view of the unit shown in FIGURE6, the section being taken on line 7-7 or FIGURE 6; and

FEGURE 8 is a fragmentary cross section View of the enclosureillustrated in FlZGURlES 6 and 7, showing the upper end of a modifiedsound chamber structure.

Referring more specifically to the drawings, numeral 1% designatesgenerally the enclosure for the present sound reproduction system, onlythe frame 12 and a picture it being visible when the enclosure ismounted on the wall or other suitable supporting structure. The picture,which is merely decorative, consists of a porous cloth or canvas havingany suitable picture, as an original or reproduction, thereon. As isseen in FEGURE 2, the frame is relatively shallow resembles aconventional picture frame with the front edge 16 thereof being somewhatsmaller than the rear edge 18.

The frame consists of two vertical side members 29 and 2-2, a top member24, and a bottom member 26, the four members being joined at the cornersand secured rigidly together by glue, cement or other suitable securingmeans and by a locking strip 28 in each corner, the joint beingreinforced if desired by one or more nails or pins in the corners. Thefront panel 3% on which cloth 14 is loosely placed is preferablyconstructed of a one piece pressed or particle board and is securedrigidly in place in frame 1.2. against shoulder 32 along the inner edgeof the frame. The front panel 36* is secured firmly against shoulder 32by vertical strips 34 and 36 along the opposite edges of the panel, andupper and lower strips 33 and ll respectively, the strips being firmlyattached to the frame by glue, cement and screws or brads. The structurethus far described is rigid and, once formed, is not intended to bedisassembled either for shipping, installation or repairs.

Previous to the present invention, it had been diificult to obtain good.bass response without a large enclosure. The present invention asembodied in the enclosure shown in the drawings has made it possible toreduce the size and provide a thin silhouette structure which givesoptimum tones throughout the entire range, i.e. the unit is constructedand designed to produce a full undistorted frequency range withelimination or minimizing of sympathetic vibrations in the frame orenclosure structure.

The present thin silhouette enclosure has been partly made possible bythe development in recent years of a speaker having a low silhouetteframe of good tone quality; however, this type of speaker has not in andof itself produced the desired low or bass tone quality in the pastwithout a conventional, relatively deep enclosure.

The present structure has eliminated the requirement of a deep enclosureby incorporating in the present thin silhouette enclosure a special bassand low tone sound chamber, designated generally in the drawings bynureral in the present unit, a large circular opening 42 is provided inthe lower portion of front panel 3d for speaker 35, which is secured tothe back side of front panel by a plurality of screws or bolts 4 3,extending through the rim of too speaker and through holes in the panelalong the edge of opening 42. The

- details of the speaker will not be described herein inasmuch as theconstruction and operation of the speaker are well known and readilyavailable from commercia sources.

In the embodiment shown in FIGURES 3, 4 and 5, the front panel isprovided with an elongated bass slot 59, positioned horizontally in theupper end of front panel 3t) and extending a substantial distancethereacross. This slot which is preferably rectangular in shape isplaced at the upper end of sound chamber 41, which consists of a panel52 paralleling front panel 30 and two side wall members 54- and 5esecured by glue or cement to the inner side of front panel 30 and tosound chamber panel 52, forming a rigid wall structure defining thesound chamber. The lower and upper ends of the sound chamber are open topermit the sound and air vibrations created by speaker 43 to enter thesound chamber unobstructed and to transmit the sound to and discharge itfrom slot 5'!) without distortion or sympathetic vibration. As shown inthe drawings, the upper end of the sound chamber, while being thesmaller end of the chamber, overlaps bass slot 5% throughoutsubstantially its full length; however, the slot is exposed at thelefthand side, as viewed in FIGURE 4, to the internal chamber of theenclosure, thus permitting the full effect of the internal chamber withrespect to the lower tones to be utilized in producing undistorted,natural low tones produced by the speaker.

The enclosure is sound insulated by fiberglas layers 60, or othersuitable material, placed throughout the length of the internal sidewalls and throughout the entire center portion of back panel 62, asshown in FIGURE 5, the insulating material preferably being secured tothe internal walls and back panel by glue or cement, without the use ofany metallic securing means, such as staples, brads or nails. The wiringfor the speaker is shown in FIGURE 4, consisting of two lead wires 64and 66, entering the enclosure at terminal 6% at the top thereof. Theterminal may be placed at any other suitable location, depending uponthe intended installation. The assembled unit is supported on a wall inmuch the same manner as a conventional picture with fixtures beingattached to the back side 18 of frame 12. along the upper half thereof.Preferably, the enclosure contacts the wall only at the lower portion,thereby leaving an air space between the enclosure and the wall forfurther effective sound resonating purposes.

The embodiment of the present invention, as shown in FIGURES 6, 7 and 8,is substantially the same as shown in the previously described figures,with the exception of the sound chamber hi) and slot 82, and hence likenumerals will be used to designate like parts. In this modified form,the sound chamber which increases in size from the lower end adjacentspeaker 43 to bass slot 82, consists of eight basic chambers, numerals8d, 86, 85, 9t), 92, 94%, as and 98, of compartments A and B, separatedby vertical strips or partitions 1&2, ltld, 1%, 1%, 11b, 112, 114 andlid, secured to panels 126*, 122, 124, 126, 12d, 13%, 132 and 134respectively, to form the individual basic tone chambers. The externaledges of the chambers are formed by wall members or strips 138,separating the various panels. The sound chamber of the foregoingconstruction is secured rigidly to the internal side of panel and thelower ends of the respective chambers are open and adjacent to thespeaker, and the upper ends of the respective chambers terminate alongslot 37.. In this modification, the bass slot is slightly longer andwider than slot 5d and is substantially embraced by the sound chamber.

in both forms system disclosed herein, better bass reproduction isobtained by tilting the upper edge of the speaker away from the rear ofthe front panel approximately one-quarter of an inch while retaining thelower edge against the panel. The modified form of the present soundreproduction system is assembled and mounted on the wall in the samemanner as the embodiment of the invention previously described. in bothof the embodiments, a suitable picture or other a, type of grid isplaced over the entire front panel and secured thereon only at itsedges.

While only two embodiments of the present invention have been describedin detail herein, various changes and modifications may be made tosatisfy requirements.

I claim:

1. A sound reproduction system, comprising a wooden frame, a front panelin said frame adjacent the front edge thereof having a large circularopening in the lower portion thereof and offset to one side, a speakerof low silhouette mounted on the rear side of said panel and securedrigidly thereto over said opening, an elongated rectangular bass and lowtone slot positioned horizontally adjacent the upper end of said frontpanel, a sound chamber construction positioned between said opening andslot adjacent said front panel and including a panel having upwardly andoutwardly tapered sides and a small open end at the bottom and a largeend at the top and being spaced from the parallel with said front paneland having its small end toward the speaker, walls along the two sidesof said last mentioned panel, said chamber being open at the bottomadjacent to the speaker and communicating at its upper end with saidslot, a panel forming a back secured to the rear edge of said frame, andsound insulating material on the internal walls of said frame and onsaid last mentioned panel.

2. A sound reproduction system, comprising a frame, a front panel insaid frame adjacent the front edge thereof having a large circularopening in the lower portion thereof, decorative material over saidpanel on the front thereof, .a speaker mounted on the rear side of saidpanel and secured rigidly thereto over said opening, an elongatedrectangular bass and low tone slot positioned horizontally adjacent theupper end of said front panel, a sound chamber construction positionedbetween said opening and slot adjacent said front panel and including apanel having upwardly and outwardly tapered sides and a small open endat the bottom and a large end at the top and being spaced from andparallel with said front panel and having its small end toward thespeaker, walls along the two sides of said last mentioned panel, saidchamber being open at the bottom adjacent to the speaker andcommunicating at its upper end with said slot, and a panel forming aback secured to the rear edge of said frame.

3. A sound reproduction system, comprising a frame, a front panel insaid frame adjacent the front edge thereof having a large circularopening in the lower portion, a speaker mounted on the rear side of saidpanel and secured rigidly thereto over said opening, an elongatedrectangular bass and low tone slot positioned horizontally adjacent theupper end of said front panel, a sound chamber construction positionedbetween said opening and slot adjacent said front panel and including aseries of panels having upwardly and outwardly tapered sides and a smallopen end at the bottom and a large end at the top and being spaced fromone another and parallel with said front panel forming a series of eightcompartments, the small end of which being disposed adjacent to theupper edge of the speaker, the large end of which being disposedadjacent to and incommunication with said slot, vertical partitionsdividing each of said compartments, and a panel forming a back securedto the rear edge of said frame.

4. A sound reproduction system, comprising a frame, a front panel insaid frame adjacent the front edge thereof having an opening in thelower portion, a speaker mounted on the rear side of said panel oversaid opening, an elongated bass and low tone slot positionedhorizontally adjacent the upper end of said front panel, a sound chamberconstruction positioned between said opening and slot adjacent saidfront panel and including a series of panels having upwardly andoutwardly tapered sides and a small open end at the bottom and a largeend at the top and being spaced from one another and parallel with saidfront panel forming a series of compartments, the small end of whichbeing disposed adjacent to the upper edge U of the speaker, and thelarge end of which being disposed adjacent to and in communication withsaid slot.

5. In a sound reproduction system: a front panel having an opening inthe lower portion, a speaker mounted on the rear side of said panel oversaid opening, an elongated slot positioned horizontally adjacent theupper end of said front panel, and a sound chamber constructionpositioned between said opening and slot adjacent said front panel andincluding a series of panels having up- Wardly and outwardly taperedsides and a small open end at the bottom and a large end at the top andbeing spaced from one another and parallel With said front panel forminga series of compartments, the small end of which being disposed adjacentto the upper edge of the speaker, the large end of which being disposedadjacent to and in communication with said slot.

6. In a sound reproduction system: a front panel having an opening inthe lower portion, a speaker mounted on the rear side of said panel oversaid opening, an elongated slot positioned horizontally adjacent theupper end of said front panel, and a sound chamber constructionpositioned between said opening and slot adjacent said front panel andincluding a series of parallel panels being spaced from one another andparallel with said front panel forming a series of compartments,interposed between and communicating with said speaker and slot.

References Cited in the file of this patent UNITED STATES PATENTS2,757,751 Tavares Aug. 7, 1956 2,792,069 Gately May 14, 1957 2,840,181Wildman June 24, 1958 2,992,695 Everitt July 18, 1961 FOREIGN PATENTS102,684 Australia Dec. 2, 1937

1. A SOUND REPRODUCTION SYSTEM, COMPRISING A WOODEN FRAME, A FRONT PANELIN SAID FRAME ADJACENT THE FRONT EDGE THEREOF HAVING A LARGE CIRCULAROPENING IN THE LOWER PORTION THEREOF AND OFFSET TO ONE SIDE, A SPEAKEROF LOW SILHOUETTE MOUNTED ON THE REAR SIDE OF SAID PANEL AND SECUREDRIGIDLY THERETO OVER SAID OPENING, AN ELONGATED RECTANGULAR BASS AND LOWTONE SLOT POSITIONED HORIZONTALLY ADJACENT THE UPPER END OF SAID FRONTPANEL, A SOUND CHAMBER CONSTRUCTION POSITIONED BETWEEN SAID OPENING ANDSLOT ADJACENT SAID FRONT PANEL AND INCLUDING A PANEL HAVING UPWARDLY ANDOUTWARDLY TAPERED SIDES AND A SMALL OPEN END AT THE BOTTOM AND A LARGEEND AT THE TOP AND BEING SPACED FROM THE PARALLEL WITH SAID FRONT PANELAND HAVING ITS SMALL END TOWARD THE SPEAKER, WALLS ALONG THE TWO SIDESOF SAID LAST MENTIONED PANEL, SAID CHAMBER BEING OPEN AT THE BOTTOMADJACENT TO THE SPEAKER AND COMMUNICATING AT ITS UPPER END WITH SAIDSLOT, A PANEL FORMING A BACK SECURED TO THE REAR EDGE OF SAID FRAME, ANDSOUND INSULAT-